As is well known, intercostal catheters have a distal end which may be inserted into the plural cavity of a patient for maintaining a negative pressure in the plural cavity where required and/or to remove wound drainage fluid from a wound or surgical incision to aid the healing process.
In U.S. Pat. No. 3,295,527, an intercostal catheter is shown having a funnel-like proximal end formed at an angle to the longitudinal axis of the tube and which has a point at the proximal tip. The distal end is a blunt end normal to the axis of the tube and is provided with a plurality of drainage openings in the sidewall adjacent the distal end. The proximal end may serve as a tube connector for connecting tubing to a drainage collection system that may include a source of suction. Where a surgical incision has been made for performing surgery, the proximal end is generally inserted through the surgical incision and then pulled, such as with forceps, through a secondary incision to the exterior of the patient until the distal end moves into the desired location within the patient. As the forceps pull the proximal end through the second incision, the open proximal end of the catheter tends to close reducing damage to the patient. The proximal end of the cath ter is formed in accordance with that patent by placing the tubing from which it is formed in a clamp, pressing the tube flat, and then cutting at the desired angle.
In cases where the chest of the patient is closed, for example, where there has been no incision into the plural cavity or open chest surgery but where there has been a puncture of the lung or other internal damage, such as due to an accident, the distal end of an intercostal catheter can be pinched, such as by forceps or by the fingers, and forced or tunneled from the exterior of the patient through an entrance incision, such as a stab wound or incision which passes between the ribs of the patient. Such a catheter may be connected to a suction source to maintain the plural cavity at a negative pressure to allow the lung to expand for breathing and so that fluid can readily drain from the wound.
Where the distal end of the catheter has a blunt end or is formed normal to the longitudinal axis of the tube, and is squeezed by the fingers or by forceps and moved into the incision from the exterior of the patient, the opposed sides of the substantially flattened end tend to increase in size and present a wide tube end extending normal to the tube axis. As a result, the catheter tends to tear or otherwise damage flesh during its movement through the incision into its desired location within the patient. In some other catheter constructions, undesirable protuberances occur when the distal end of the intercostal catheter is flattened during insertion.
Trocar catheters have also been used for closed-chest drainage. However, insertion of the catheter and pointed trocar into the patient has the potential danger of damaging the patient, such as piercing the lung, as a result of the insertion technique.